import { apiRequestData } from "../api/http";
import { verifyEmailLoginCode } from "../api/auth";
import type { LoginRequest, LoginResponse, MeResponse } from "../api/types";
import { getDeviceFingerprint } from "./deviceFingerprint";

const JSON_HEADERS = {
  "content-type": "application/json",
};

const REFRESH_SUCCESS_REPLAY_MS = 1000;

let refreshSessionPromise: Promise<LoginResponse> | null = null;
let refreshSessionReplay: { data: LoginResponse; expiresAt: number } | null = null;
let refreshSessionGeneration = 0;

export function resetRefreshSessionCache() {
  refreshSessionGeneration += 1;
  refreshSessionPromise = null;
  refreshSessionReplay = null;
}

export async function loginWithPassword(payload: LoginRequest) {
  resetRefreshSessionCache();
  return apiRequestData<LoginResponse>("/api/auth/login", {
    method: "POST",
    auth: false,
    retryOn401: false,
    headers: {
      ...JSON_HEADERS,
      "x-device-fingerprint": getDeviceFingerprint(),
    },
    body: JSON.stringify(payload),
  });
}

export async function loginWithEmailCode(payload: { email: string; code: string }) {
  resetRefreshSessionCache();
  return verifyEmailLoginCode(payload);
}

async function requestRefreshSession() {
  return apiRequestData<LoginResponse>("/api/auth/refresh", {
    method: "POST",
    auth: false,
    retryOn401: false,
    headers: {
      "x-device-fingerprint": getDeviceFingerprint(),
    },
  });
}

export async function refreshSession() {
  const now = Date.now();
  if (refreshSessionReplay && refreshSessionReplay.expiresAt > now) {
    return refreshSessionReplay.data;
  }

  if (!refreshSessionPromise) {
    const generation = refreshSessionGeneration;
    const requestPromise = requestRefreshSession()
      .then((data) => {
        if (generation === refreshSessionGeneration) {
          refreshSessionReplay = {
            data,
            expiresAt: Date.now() + REFRESH_SUCCESS_REPLAY_MS,
          };
        }
        return data;
      })
      .catch((error: unknown) => {
        if (generation === refreshSessionGeneration) {
          refreshSessionReplay = null;
        }
        throw error;
      });

    refreshSessionPromise = requestPromise;
    void requestPromise
      .finally(() => {
        if (refreshSessionPromise === requestPromise) {
          refreshSessionPromise = null;
        }
      })
      .catch(() => undefined);
  }

  return refreshSessionPromise;
}

export async function logoutSession() {
  try {
    return await apiRequestData<Record<string, never>>("/api/auth/logout", {
      method: "POST",
      auth: false,
      retryOn401: false,
    });
  } finally {
    resetRefreshSessionCache();
  }
}

export async function fetchCurrentEmployee(accessToken: string) {
  return apiRequestData<MeResponse>("/api/me", {
    auth: true,
    retryOn401: false,
    accessTokenOverride: accessToken,
  });
}